Automatic cleaning-hammer.



Patented Jan. 26, 1915.

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head 14 is adapted to ride. handle 15 which carries the head 14 consists UNTTD STATES ATEN T FFTQE.

Specification of Letters Patent.

Application filed August 18, 1914. Serial No. 857,377.

To all whom it may concern:

Be it known that I, ADoLPH N. BRAGSTAD, a citizen of the United States, residing at Canton, in the county of Lincoln and State of South Dakota, have invented certain new and useful Improvements in Automatic Cleaning-Hammers, of which the following is a specification.

This invention relates to certain new and useful improvements in automatic cleaning hammer for concrete mixing drums.

The primary object of this invention is to provide any of the usual forms of revolving mixing drums with an automatic means for imparting sudden jars thereto, and maintaining the drum clear of the contained material and preventing any clogging thereof.

A further object is to provide a tripping hammer automatically actuated for striking a mixing drum and being simple and inexpensive in its mechanical construction.

It is also designed to provide a hammer traveling by a roller on the hammer and over the surface of the drum and automatically raised for compressing a spring and when tripped violently contacting the drum for cleaning the same of its contents.

With these general objects in view and others that Will appear as the nature of the invention is better understood, the same consists in the novel combination and arrangement of parts to be hereinafter more fully described and claimed.

In the drawings forming a part of this application and in which like designating characters refer to corresponding parts throughout the several views, Figure l is a side elevational view of the device. Fig. 2 is a transverse sectional view taken through the drum and showing the hammer with parts thereof partially broken away, and Fig. 3 is a perspective View of the lower end portion of the hammer.

Referring more in detail to the drawings, the revolving drum 10 is illustrated herein of substantially the usual construction, being adapted for mixing concrete or similar material, and supported by the framework 11. An encircling band 12 is provided around the drum 10 and constitutes a track or way against which a roller 13 ofahammer The hammer of a metallic rod having its lower end 16 outwardly curved while an angular arm. or extension 17 laterally projects from one side thereof.

A U-shaped bracket 18 is rigidly mounted upon the frame 11 and is provided with a pivot rod 19, upon which the hammer handle 15 is journaled between the opposite sides of the bracket 18 by having said rod 19 projecting through alining perforations 20 of the handle 15 and extension 17 thereof. A coil spring 21 isiinked to the free end of the handle end 16 and is adjustably attached to a strap 22 of an upper portion 23 of the machine frame. Cam plates 24 outwardly project from the surface of the drum l0 and are positioned at one side of the track band 12, the said plates being equally spaced apart peripherally of the drum, and have upwardly inclined face portions 25. A stub shaft 26 projects from the hammer handle 15 upon the side thereof opposite to the extension 17, and intermediately positioned with respect to the head 14:, and the pivot rod 19. A roller 27 is journaled upon the shaft 26 and is positioned for engagement with the cam plates 24 when traveling thereunder.

In operating, the drum 10 revolves in a direction indicated by the arrow in Fig. 2, and the hammer roller 13 normally travels upon the track 12 during such rotation, and is maintained in contact therewith by the normal tension of the spring 21. During such rotation of the drum, the cam plates 24 are successively brought in contact with the side roller 27 of the hammer handle, which roller is thereby made to travel upwardly of the inclined portion 25 of the contacted cam, which elevating of said roller and the adjacent handle end further tensions the spring 21. When the roller 27 reaches the free rearward end 28 of the cam plate, the said roller rides off of the same and by reason of the sudden release of the spring 21, the hammer roller 13 is violently brought into contact with the track 12. It will be evident that as many violent contacts or blows will be administered to the drum by the hammer as there are cam plates provided thereon. This arrangement it will be seen provides an automatic means for raising the hammer from the drum and simultaneously tensioning the operating spring as well as the automatic tripping of Patented Jan. 26, 1915'..-

the hammer for-stwcessively contacting the hammer in violent blows against the drum which results in agitating the contents of the latter. As will be obvious, impacts resulting-from the contact between the cams and lateral thrust exerted upon the hammer 15 which Will tend to distort it, and also to, transmit a destructive pressure upon the pivot pin 19. To obviate this, and to insure a proper alinement of the hammer handle-relative to the cams, the hammer handle isscaused to bear against the inner face of one arm of the bracket, While the outer terminal of the. arm 17 bears against the other armof thebracket, and the, pivot pin. 19

passes through the two bracket arms, the hammer handle and the up-turned the, arm 17 tendency to lateral deflection of the hammer handle, Will be prevented, and'the strain r on the pivot pin Will betransmitted to the arm-17 and will thusbe equalized.

While the'form of the invention herein shown, and described is What is believed to bethepreferable embodiment, thereof, minor, changes'vmay be made Without depart- Gogi es 0:, this patent may be obtained for five centsieach bytacldressingfihe Washington, 11, 0.

under the i the roller 27, there. Willbe a.

end of Under these conditions, anyv ingfrom the spirit andscope of the invention as set forth in the claim.

What I claim as new is Inaconcrete mixer, the combination'vvith a frame, and a drum revolubly mounted thereon, of spaced cams carried by the drum, a tWo-armed bracket secured to the frame, a hammer having its handle bearing against the inner side of one of the bracket arms,-a roller p rojecting laterally from one side of the an arm on the oppositesideof the handle and bearing against the inner-side of the other bracket arm to: brace the againstyielding-from lateral strain due to impact betweeni-the= roller and the cams, a

handle in the path of the cams,

handle 1 pivot rod passing throughthe bracket arms,

handle and brace arms, and resilient means for causing the hammer headnormally to contact with the 1 drums Intestimonywhereof I aflix my signature in presence of twowitnessesr DOL HJN BRA S AD Vitnesses OLE OSHEIM, H; A. HANSON:

Commissioner of Yatents, 

